Spoiler alert: Minor spoilers for the TV show Orphan Black, as well as spoilers for other pieces of (less-contemporary) content, discussed throughout.

Nearly 18 years ago, the world said hello to its first clone of an adult mammal. Frogs and other mammal trials had come before Dolly, but she was a special sheep, sourced straight from another sheep’s mammary glands, no sperm necessary. Instead, Dolly’s creators replaced an egg’s DNA with that of the source cell, then tricked the egg into thinking it had been fertilized.

A year later, she was formally announced to the world, and its largest governing bodies jumped to conclusions with a loud reply. Humans can’t be next, they cried! President Bill Clinton and the FDA quickly and formally expressed their disapproval of human cloning trials. Over two dozen countries still either ban human trials outright or limit the practice to research, only forbidding full-term births. (Such human research is alive and well, as we recently reported.)

Meanwhile, the world watched Dolly carefully, wondering whether a clone could live a normal, healthy life while weighing the differences between nature and nurture. For her part, Dolly had a few babies, was diagnosed with arthritis at 4 years, and died at the age of 6, short of the 10-11 year lifespan of an average sheep.

What’s less known about Dolly is that she lives on, kinda-sorta. Her original research team produced four more Dolly-like sheep in 2007, which were projected to live normal, healthy lives when they were revealed to the world three and a half years later. (We asked the University of Nottingham about those Dollies’ current status; if they’re still alive, then they have officially outlasted their more famous genetic peer.)

Either way, the Dollies’ story is worth noting in light of another clone-centric event this weekend: the second-season premiere of the BBC’s extraordinary TV series Orphan Black, which has one actress portraying (at least) 11 different women. Just as cloning has existed as a major scientific effort for decades, so too has sci-fi toyed with it, and those treatments have ranged from weird to funny to downright dystopian.

But as the science of animal cloning has become more refined, so have the tales and series that obsess over the (generally, technically illegal) human possibilities.

History of sci-fi clones, part one

High school go-to novel Brave New World by Aldous Huxley didn’t involve cloning, but it was the first widely-read piece of sci-fi to explore its most sensitive elements. Decades before test-tube babies became a reality, Aldous Huxley released his story of selective genetic breeding, and its core theme—free will in the face of societal pressure—resonated in a lot of clone-obsessed sci-fi in the years to come.

Conversely, another British sci-fi author, William F. Temple, can claim responsibility for one of cinema’s earliest, and cheesiest, takes on the world of cloning. The movie The Four-Sided Triangle, based on the novel of the same name, tells the classic story of boy-meets-girl, girl-falls-for-other-boy, boy-clones-girl (to requite his love). Sad Bill figured he could solve his problems by cloning beautiful Lena in a terrifying device called the Reproducer, which could make a one-for-one copy of anything, living or inanimate. But the Reproducer worked a little too well, even cloning her infatuation with Bill’s romantic rival. (Nothing a little brain reprogramming couldn’t fix.)

After more writers explored the ideas and challenges of human cloning, Ira Levin’s 1976 novel The Boys From Brazil (also a 1978 film starring Gregory Peck) emerged with a more pronounced take on the premise. It wrapped a tale of murder, intrigue, and Nazis around a reasonably believable version of cloning, at least for the time. Surrogate mothers received the same source DNA and gave birth to babies that were then posted around the world for adoption.

Levin’s treatment obsessed more over “nurture” than “nature,” however, as each of the story’s 94 clones were placed in families with specific restrictions: the fathers had to be a little over two decades older than the mothers, and those fathers, who worked in civil service and were cantankerous coots, had to die at the age of 65. SPOILER: The story’s secret society hoped that’d turn at least one of these clones into a damaged duplicate of DNA-source Adolph Hitler, ignoring all of the other societal and regional factors that probably played into Hitler Prime’s development.

In spite of that dark theme, sci-fi’s most dystopian take on cloning might actually come from Hatching Stones, an Anna Wilson novel from 1991 that explores the technology’s potential for narcissism. It describes a world in which a male-dominated society takes control of cloning and chooses to produce clones of themselves, as opposed to traditional mating, to create an all-male society. In response, the women do not rise up in united Lysistrata fashion; instead, they are banished to their own island, where they begin their own, female-focused cloning trials. This schism speaks greatly to the darkest direction a cloning-capable society might go—not that we’d genetically select for perfection, but that we’d assume we, the creators, are already the perfection worth striving toward.

A copy of a copy?

Only in recent years has cloning been handled with much of an overt sense of humor. Multiplicity is the most prominent example, particularly in treating the process like a Xerox machine (hence, the copy-of-a-copy of star Michael Keaton is the dumb, slapstick version), while MTV’s Clone High cloned some of history’s most famous names (Cleopatra, Gandhi, Abraham Lincoln) and showed audiences how they might interact together as bumbling, insecure teenagers.

Orphan Black has its moments of levity, but more importantly, the BBC series allows nature-versus-nurture themes to breathe over a serialized span. The series opens with “main” clone Sarah Manning meeting a seemingly exact copy, named Beth Childs, just as Beth kills herself. Down on her luck, Sarah decides to adopt Beth’s more successful identity, and she sets out on an identity-theft scam that quickly unravels, just as she begins to learn about other clones and how they’re all connected.

The clones, all masterfully portrayed by actress Tatiana Maslany, come from soundly different upbringings and vocations, and they’re portrayed as unflinchingly individual women. But once they meet, they begin to question their longtime identities and take inspiration from their genetic peers. In particular, woeful housewife Alison gets a rare glimpse at a question we probably all pose to ourselves: What would I be like in an alternate universe? Once she meets her more forward and cutthroat peers, she begins to act out accordingly and, as a result, is perhaps the series’ most intriguing character.

Their stories revolve around questions of identity—which clone is the “best” one, what do our upbringings actually mean—and ethics—what happens when test subjects turn into full-fledged people? This upcoming season is set to explore just as many questions about identity for characters whose mirror images are a mix of funhouse distortions and stark similarities, while hints of potential love triangles may excite fans of The Four-Sided Triangle (we can only hope Orphan Black handles them with more grace, of course).

While Orphan Black shines thanks to stellar writing and incredibly clean green-screen effects, it also benefits from a long line of both real science and sci-fi exploration. How does the human condition change when stared in the eyes by exact genetic copies, and how does that relate to our own, clone-free struggles with identity and scientific ethics?

The result is a wonderfully blurry line where sci-fi brings out the best in self-discovery and storytelling, and that line’s zillions of examples couldn’t possibly fit in one love letter to sci-fi’s best clones. Be sure to celebrate your favorites in the comments (so long as you don’t, you know, duplicate anybody else’s.)